Java Java Data Structures Efficiency! Using a Map to store Contact Methods

I am not sure what Is wrong with my code.

For this task, let's fix the getContactInfo method.

That is the question.

com/example/model/Contact.java
package com.example.model;

import java.util.Map;
import java.util.Set;
import java.util.HashMap;

public class Contact {
  private String mFirstName;
  private String mLastName;
  private Map<String, String> mContactMethods;

  public Contact(String firstName, String lastName) {
    mFirstName = firstName;
    mLastName = lastName;
return mapName.keySet();
    mContactMethods = new HashMap<String, String>();
  }

  public void addContactMethod(String method, String value) {
   mContactMethods.put(method, value);
  }

  /**
   * Returns the available contact methods.  eg: phone, pager,
   *
   * @return The name of the contact methods that are available
   */
public Set<String> getAvailableContactMethods() {
    return mContactMethods.keySet();
  }

  /**
   * Returns the value for the contact method if it exists, 
   *
   * @param methodName  The name of the contact method to look up.
   * @return The name of the contact methods that are available
   */
public String getContactInfo(String methodName) {
mContactMethods.get(contacts); 
  return methodName;
}

  public String getFirstName() {
    return mFirstName;
  }

  public String getLastName() {
    return mLastName;
  }

}
David Axelrod
David Axelrod
36,073 Points

what is the compiler saying?

these challenges were tough

1 Answer

David Axelrod
David Axelrod
36,073 Points

just went back and did the challenge again

this code passed

in your getContactInfo method you were returning the parameter and were using "contacts" as the key.

if you condense it to one line and just use the passed in "methodName" as the param for get, you should be good to go!!

hope this helps!

  public void addContactMethod(String method, String value) {
    // TODO: Add to the contact method map

    mContactMethods.put(method, value);


  }

  /**
   * Returns the available contact methods.  eg: phone, pager,
   *
   * @return The name of the contact methods that are available
   */
  public Set<String> getAvailableContactMethods() {
    // FIXME: This should return the current contact method names.
    return mContactMethods.keySet();
  }

  /**
   * Returns the value for the contact method if it exists, 
   *
   * @param methodName  The name of the contact method to look up.
   * @return The name of the contact methods that are available
   */
  public String getContactInfo(String methodName) {
    // FIXME: return the value for the passed in *methodName*

    //return a value for the key of method
    return mContactMethods.get(methodName);
  }

Thanks so much. This helped a lot.

why did you use .put instead of .add

David Axelrod
David Axelrod
36,073 Points

Good question. I think it's because we are using a map rather than a list. Put is the method to add to a map whereas add is used for a list. I think they might have the same functionality though! Here's a few links that might clear things up! Add Vs. Put

Thanks